MRT-2 checkpoint protein is required for germline immortality and telomere replication in C. elegans

Nature. 2000 Jan 13;403(6766):159-64. doi: 10.1038/35003120.


The germ line is an immortal cell lineage that is passed indefinitely from one generation to the next. To identify the genes that are required for germline immortality, we isolated Caenorhabditis elegans mutants with mortal germ lines--worms that can reproduce for several healthy generations but eventually become sterile. One of these mortal germline (mrt) mutants, mrt-2, exhibits progressive telomere shortening and accumulates end-to-end chromosome fusions in later generations, indicating that the MRT-2 protein is required for telomere replication. In addition, the germ line of mrt-2 is hypersensitive to X-rays and to transposon activity. Therefore, mrt-2 has defects in responding both to damaged DNA and to normal double-strand breaks present at telomeres. mrt-2 encodes a homologue of a checkpoint gene that is required to sense DNA damage in yeast. These results indicate that telomeres may be identified as a type of DNA damage and then repaired by the telomere-replication enzyme telomerase.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amino Acid Sequence
  • Animals
  • Base Sequence
  • Caenorhabditis elegans
  • Caenorhabditis elegans Proteins*
  • Cell Survival
  • DNA Damage
  • DNA Replication
  • DNA, Helminth / biosynthesis
  • DNA, Helminth / genetics
  • Genes, Helminth
  • Germ Cells / physiology*
  • Helminth Proteins / genetics
  • Helminth Proteins / physiology*
  • Humans
  • Molecular Sequence Data
  • Mutation
  • Sequence Homology, Amino Acid
  • Telomere*


  • Caenorhabditis elegans Proteins
  • DNA, Helminth
  • Helminth Proteins
  • MRT-2 protein, C elegans

Associated data

  • GENBANK/AF073524
  • GENBANK/AF074718
  • GENBANK/AF076843
  • GENBANK/AF124501
  • GENBANK/P14746
  • GENBANK/P22193
  • GENBANK/P48581